{"Bibliographic":{"Title":"Benthic invertebrates, sediment characteristics, and demersal fishes off Cottonwood Island, Columbia River, before and after rock groin construction, 1987-1988","Authors":"","Publication date":"1990","Publisher":""},"Administrative":{"Date created":"08-16-2023","Language":"English","Rights":"CC 0","Size":"0000062954"},"Pages":["153\nn513\n3\nBenthic Invertebrates, Sediment Characteristics,\nand Demersal Fishes\nOff Cottonwood Island, Columbia River,\nBefore and After Rock Groin Construction,\n1987-1988\nby\nGeorge T. McCabe, Jr., Susan A. Hinton,\nRobert L. Emmett, and Robert J. McConnell\nJuly 1990\nLibrary\nCOASTAL\nZONE\nSTUDIES","NWFSC045\nBENTHIC INVERTEBRATES, SEDIMENT CHARACTERISTICS, AND DEMERSAL\nFISHES OFF COTTONWOOD ISLAND, COLUMBIA RIVER, BEFORE AND AFTER\nROCK-GROIN CONSTRUCTION, 1987-1988\nLibrary\nNorthwest\nSeattle Montlake 2725 NOAA. National & Alaska Fisheries Center\nMarine\nWA Fisheries E. Service\nSH\nby\nGeorge T. McCabe, Jr.\n153\nSusan A. Hinton\nRobert L. Emmett\nUn513\nand\nRobert J. McConnell\nFinal Report\nFunded by\nU.S. Army Corps of Engineers\nPortland District\nP. O. Box 2946\nPortland, Oregon 97208\n(Project Number DACW57-87-F-0641)\nand\nCoastal Zone and Estuarine Studies Division\nNorthwest Fisheries Center\nNational Marine Fisheries Service\nNational Oceanic and Atmospheric Administration\n2725 Montlake Boulevard East\nSeattle, Washington 98112-2097\nJuly 1990","CONTENTS\nPage\nINTRODUCTION\n1\nMETHODS\n1\nRESULTS\n5\nBenthic Invertebrates\n5\nSediment Characteristics\n9\nDemersal Fishes\n12\nDISCUSSION\n12\nACKNOWLEDGMENTS\n16\nLITERATURE CITED\n17\nAPPENDIX\n18","1\nINTRODUCTION\nIn 1987, the National Marine Fisheries Service (NMFS) entered\ninto a cooperative agreement with the U.S. Army Corps of Engineers\n(COE) to study benthic invertebrates, sediment characteristics, and\ndemersal fishes near pile dikes and rock groins at Cottonwood\nIsland (Dobelbower Bar) in the Columbia River. Pile dikes in the\nColumbia River are used to help maintain the navigational channel\nand reduce maintenance dredging costs.\nFrom 1925 to 1969, fifteen wooden pile dikes were constructed\nalong Cottonwood Island (COE 1987) . Over the years these pile\ndikes deteriorated and by 1987 most of the dikes were in poor\ncondition. In early 1987, the COE proposed to replace seven of the\npile dikes with submerged rock groins by placing rock along and\naround the existing pile dikes (COE 1987) . Because of the paucity\nof information about benthic invertebrates and demersal fishes,\nparticularly white sturgeon (Acipenser transmontanus), , near the\npile dikes, the COE arranged for NMFS to conduct four environmental\nsurveys in the vicinity of the pile dikes and rock groins. Two\nsurveys were to be done prior to rock groin construction and two\nafter construction to assess short-term changes in the benthos and\ndemersal fish community.\nMETHODS\nFour benthic surveys were conducted at six stations near the\npile dikes and rock groins along Cottonwood Island; the sampling","2\nstations ranged from River Mile (RM) 68.4 to 70.6 (Fig. 1; Appendix\nTable 1) . The first two surveys, July and November 1987, were\nprior to the rock-groin construction and the last two, July and\nDecember 1988, were after the construction. Construction began in\nJanuary 1988 and was completed in March 1988. Five benthic\ninvertebrate samples and one sediment sample were collected at each\nstation using a 0.1-m2 Van Veen grab sampler (Word 1976) . When\npractical, each benthic invertebrate sample was sieved through a\n0.5-mm screen and the residue preserved in a buffered formaldehyde\nsolution (>4%) containing rose bengal, an organic stain. If it\nappeared that most of the sample would not wash through the sieve,\nthen the entire sample was preserved and sieved at a later time.\nLater the samples were washed with water and preserved in a 90%\nethyl alcohol solution to prevent the destruction of calcareous\ninvertebrate parts by formaldehyde. Each benthic invertebrate\nsample was sorted and the invertebrates were identified to the\nlowest practical taxonomic level and counted. Sediment samples\nwere analyzed by the COE (North Pacific Division Materials\nLaboratory, Troutdale, Oregon) for sediment grain size and percent\norganic carbon (total volatile solids) .\nThe benthic invertebrate data were analyzed by station.\nInformation calculated for each station included the number of\ntaxa; total number, frequency of occurrence, and mean number/m2 and\nstandard deviation (SD) for individuals in each taxon; mean number\nof invertebrates/sample and SD; and mean number of invertebrates/m2","3\nCowlitz\nWashington\nOregon\nCW 11\nCarrolls\nCW 21\nCot\nRainier\nCW 12\nCW 22\nCW 23\nWashington\nCW 13\nOregon\nPrescott\nT\nN\nRiver\n0\n1 mile\nFigure 1. . --Locations of the benthic and bottom-trawling 1987-1988. stations Benthic off\nCottonwood Island, Columbia River, however,\nwere collected at all six stations; and\nsamples was done only at Stations CW21, CW22, groins CW23.\ntrawling The seven pile dikes that were replaced with rock are\nindicated with heavy lines.","4\nand SD. Also, two community structure indices were calculated for\neach station--Shannon-Wiener function (H') (Krebs 1978) and\nEvenness (J') (Pielou 1966) :\nS\nH' = - Pi log2Pi\ni=1\nJ' = H'/log2s\nwhere Pi = Xa/n (Xa is the number of individuals of a particular\nspecies in a sample and n is the total number of individuals in the\nsample), and S = number of species. The Shannon-Wiener function is\na diversity index that incorporates two elements of diversity-\nnumber of species and species evenness (Krebs 1978) . Evenness is a\nmeasure of the equitability of the proportional abundances of\nvarious species in the sample.\nTotal mean numbers (by station) for each survey were compared\nusing a two-sample t-test (unpaired data, assuming unequal\nvariance) ; the data were transformed to log 10 prior to making the\ncomparisons (Elliott 1977) . Mean numbers of the amphipod Corophium\nsalmonis, the bivalve Corbicula manilensis, Heleidae larvae, and\nOligochaeta were compared by survey (by station for each taxon)\nusing the t-test. The data were transformed to log 10 prior to\nanalysis. For Heleidae larvae, the data were transformed to log\n10\nof (number + 1) prior to analysis; 1 was added to the number\nbecause of one zero count.","5\nA 4.9-m (headrope length) semiballoon shrimp trawl was used to\ncollect demersal fishes near the pile dikes and rock groins at\nCottonwood Island; trawling was done slightly west or southwest of\nthe river ends of the dikes and groins. Mesh size in the body of\nthe trawl was 32 mm (stretched) ; a 10-mm mesh liner was inserted in\nthe cod end. Also, 10-mm knotless mesh was inserted in the wings\nand throat of the trawl. Trawl efforts were normally 5 minutes in\nduration in an upstream direction. Trawling began when the trawl\nand the proper amount of cable were deployed, and the effort was\nconsidered complete after 5 minutes. The distance the net fished\nwas estimated during each sampling effort using a radar range-\nfinder. Using the distance fished during trawling and the\nestimated fishing width of the net (3.3 m), the area fished for\neach effort was calculated. The fish densities (by species) for\neach effort were calculated and expressed as number/hectare (ha)\n(10,000 m²) . The two community structure indices calculated for\nbenthic invertebrates were also calculated for each trawling\neffort.\nRESULTS\nBenthic Invertebrates\nBenthic invertebrate densities (total) off Cottonwood Island\nvaried both spatially and temporally (Table 1; Appendix Table 2)\nOverall, the highest mean densities occurred during Survey 3\n(21 July 1988), with densities ranging from 3,780 to 6,506","6\nTable 1. Summary of benthic invertebrate collections off Cottonwood\nIsland, Columbia River, 1987-1988; five replicates were\ncollected at each station. A mean depth (m) and standard\ndeviation are shown for each station; depths at an\nindividual station varied among surveys.\nSurvey 2\nSurvey 3\nSurvey 4\nSurvey 1\n(7-9 Jul 87)\n(19 Nov 87)\n(21 Jul 88)\n(6-7 Dec 88)\nStation\nMean no./m2\nMean no./m2\nMean no./m2\nMean no./m2\nSD\nSD\nSD\n(Depth)\nSD\n2,407\n3,052\n1,707\n2,435\n970\n469\n5,450\n2,495\nCW11\n(3+1)\n5,569\n2,618\n817\n376\n3,135\n339\n1,418\n663\nCW21\n(12+2)\n1,123\n3,217\n718\n50\n52\n6,506\n1,978\n1,514\nCW12\n(4+2)\n1,989\n1,047\n3,780\n1,372\n3,545\n4,213\nCW22\n3,583\n2,084\n(12+3)\n3,336\n3,980\n1,844\n924\n132\nCW13\n1,149\n228\n3,719\n(4+1)\n3,924\n4,108\n1,033\n666\n600\nCW23\n876\n503\n4,206\n(11+2)","7\ninvertebrates/m2 Within each year, invertebrates tended to be more\nabundant during July as compared to November and December; numbers\nwere not significantly different for the first year (July vs\nNovember), but were significantly different (P < 0.05) for the\nsecond year (July vs December) (Table 2) Benthic invertebrate\nnumbers were significantly higher in July 1988 (post-groin\nconstruction) than in July 1987 (pre-groin construction); however,\nthere was no significant difference in invertebrate numbers between\nNovember 1987 (pre-groin construction) and December 1988 (post-\ngroin construction) . For the purposes of this study, the most\nimportant comparisons are for corresponding time periods of the two\nyears, since even undisturbed benthic invertebrate populations\nfluctuate seasonally.\nDiversity (H') was higher in July 1988 (mean 1.69) than in\nJuly 1987 (mean 1.32), and Evenness (J') values were similar for\nJuly 1987 and July 1988 (means 0.46 and 0.42, respectively). .\nThe\nprimary reason for the higher diversity in July 1988 was the\nincrease in the number of taxa, since the distribution among\nindividual species abundances (Evenness) was similar in both years.\nIn July 1988, the mean number of taxa collected at each station was\n16, whereas in July 1987, the mean number of taxa at each station\nwas 8. Both Diversity (H') and Evenness (J') were higher in\nDecember 1988 (means 1.78 and 0.52, respectively) than in November\n1987 (means 1.00 and 0.38, respectively). There were two reasons\nfor the higher diversity in December 1988--greater evenness among","8\nTable 2. -Comparisons of benthic invertebrate numbers (by specific\ntaxa and total) for the four surveys off Cottonwood\nIsland, Columbia River; total includes all invertebrates,\nnot just the dominant taxa listed below. T-test values\nare shown in the table; P values are shown in\nparentheses. The four surveys were on 7-9 July 1987,\n19 November 1987, 21 July 1988, and 6-7 December 1988,\nrespectively. Surveys 1 and 2 were prior to rock-groin\nconstruction, and Surveys 3 and 4 were after the\nconstruction.\nSurvey comparisons\nTaxon\n1 vs 2\n3 vs 4\n1 vs 3\n2 vs 4\nCorophium salmonis\n0.52 (0.62)\n3.72 (0.01)\n-2.86 (0.03)\n1.25 (0.24)\nCorbicula manilensis\n-1.03 (0.35)\n-0.89 (0.41)\n-3.69 (0.00)\n-0.97 (0.36)\nHeleidae larvae\n3.78\n(0.01)\n7.42\n(0.00)\n-3.23\n(0.02)\n-1.16 (0.29)\nOligochaeta\n1.08\n(0.31)\n1.27\n(0.24)\n-3.16 (0.01)\n-2.33 (0.04)\nTotal\n0.79 (0.46)\n4.42 (0.00)\n-3.38 (0.02)\n-0.26\n(0.81)","9\nthe species as evidenced by the higher J' in 1988 and an increase\nin the number of taxa in 1988. In December 1988, the mean number\nof taxa collected at each station was 11, whereas in November 1987,\nthe mean number of taxa at each station was 7.\nThe tube-dwelling amphipod Corophium salmonis was by far the\ndominant benthic invertebrate collected at the Cottonwood Island\nsites; mean densities ranged from 27 to 3,912/m2, with densities\nfrequently exceeding 1,600/m2 (Table 3; Appendix Table 2). Other\nimportant taxa included the bivalve Corbicula manilensis, Heleidae\nlarvae, and Oligochaeta. Corophium salmonis numbers were\nsignificantly higher in July 1988 as compared to December 1988\n(P < 0.05), yet numbers in 1987 were not significantly different\nbetween July and November (Table 2) Numbers of C. salmonis were\nsignificantly higher in July 1988 (post-groin construction) than in\nJuly 1987 (pre-groin construction); whereas numbers during the\nNovember 1987 (pre-groin construction) and December 1988 (post-\ngroin construction) surveys were not significantly different.\nNumbers of Corbicula manilensis, Heleidae larvae, and Oligochaeta\nwere significantly higher in July 1988 than in July 1987 (Table 2)\nComparing November 1987 and December 1988, numbers of Oligochaeta\nwere significantly higher in 1988.\nSediment Characteristics\nSand was the predominant sediment type at the Cottonwood\nIsland sampling stations; however, gravel was important at some\nstations (Table 4; Appendix Table 3) Organic content was less","10\nTable 3. . - Mean densities (number/m² of four dominant benthic\ninvertebrate taxa found off Cottonwood Island, Columbia\nRiver. The four surveys were on 7-9 July 1987,\n19 November 1987, 21 July 1988, and 6-7 December 1988,\nrespectively.\nSurvey 3\nSurvey 4\nSurvey 1\nSurvey 2\nStation\nTaxon\n2,079\nCorophium salmonis\n1,094\n544\n3,912\nCW11\n71\n92\nCorbicula manilensis\n27\n120\n903\n61\n479\n231\nHeleidae larvae\n225\n105\n32\n57\nOligochaeta\n132\n1,042\n3,387\nCorophium salmonis\n1,774\nCW21\n128\n464\nCorbicula manilensis\n29\n237\n136\n691\n38\n867\nHeleidae larvae\n36\n132\n8\n67\nOligochaeta\n44\n3,805\n861\nCorophium salmonis\n2,230\nCW12\n97\n2\n61\nCorbicula manilensis\n34\n105\n735\n0\n985\nHeleidae larvae\n1,504\n321\n202\n4\nOligochaeta\n2,113\n27\nCorophium salmonis\n2,690\n1,638\nCW22\n44\n281\n2,337\nCorbicula manilensis\n86\n336\n716\n67\n802\nHeleidae larvae\n472\n682\n38\n237\nOligochaeta\n2,480\n357\nCorophium salmonis\n794\n3,370\nCW13\nCorbicula manilensis\n15\n164\n80\n31\n223\n279\n160\n777\nHeleidae larvae\n57\n21\n445\n265\nOligochaeta\n242\n3,547\n2,369\nCorophium salmonis\n500\nCW23\nCorbicula manilensis\n36\n422\n139\n187\n1,176\n80\n321\n132\nHeleidae larvae\n17\n34\n275\n52\nOligochaeta","11\nTable 4. Summary of percent sediment composition at six sampling\nstations off Cottonwood Island, Columbia River. The four\nsurveys were on 7-9 July 1987, 19 November 1987, 21 July\n1988, and 6-7 December 1988, respectively. A mean depth\nand standard deviation are shown for each station; depths\nat an individual station varied among surveys.\nSurvey 2\nSurvey 3\nSurvey 4\nSurvey 1\nSd.\nFn.\nGr.\nSd.\nFn.\nStation\nGr.\nSd.\nFn.\nGr.\nSd.\nFn.\nGr.\n(Depth, m)\n29\n70\n1\n32\n68\n0\n33\n66\n1\n28\n71\n1\nCW11\n(3+1)\n31\n67\n2\n2\n44\n56\n0\n53\n47\n0\n57\n41\nCW21\n(12+2)\n89\n1\n82\n1\n6\n94\n0\n9\n91\n0\n10\nCW12\n17\n(4+2)\n90\n<1\n13\n86\n1\n11\n88\n1\n10\n3\n96\n1\nCW22\n(12+3)\n96\n<1\n90\n0\n4\n0\n5\n95\n2\n98\n0\n10\nCW13\n(4+1)\n53\n0\n69\n31\n0\n41\n0\n47\n33\n67\n0\n59\nCW23\n(11+2)\nGr. = gravel; grain size >2 mm to <64 mm.\na\nb\nSd. = sand; grain size 0.0625 to <2 mm.\nFn. = fines; grain size <0.0625 mm.\nc","12\nthan 1% at all stations during all four surveys. The proportions\nof gravel, sand, and fines at the three shallower stations (CW11,\nCW12, and CW13) generally did not change dramatically from survey\nto survey. At two of the deeper stations (CW21 and CW23), changes\nin proportions of gravel and sand between surveys were more\npronounced than at the shallower stations.\nDemersal Fishes\nDensities of demersal fishes off Cottonwood Island were\nrelatively low; total densities ranged from 10 to 176 fishes/ha\n(Table 5; Appendix Table 4). Fishes collected during the surveys\nincluded white sturgeon, peamouth (Mylocheilus caurinus), northern\nsquawfish (Ptychocheilus oregonensis), largescale sucker\n(Catostomus macrocheilus), sand roller (Percopsis transmontana),\nprickly sculpin (Cottus asper), unidentified Cottidae, and starry\nflounder (Platichthys stellatus) The mean fish density for July\n1988 (mean 130 fish/ha) was somewhat higher than the density for\nJuly 1987 (mean 100 fish/ha), and densities for November 1987 (mean\n28 fish/ha) and December 1988 (mean 29 fish/ha) were similar.\nApparently, juvenile white sturgeon were not utilizing the area to\nany great degree during the times that we sampled, since only two\njuvenile sturgeon were collected during the four surveys.\nDISCUSSION\nOverall, the installation of rock groins along Cottonwood\nIsland did not appear to adversely affect the benthic invertebrate","13\nTable 5. --Catch summaries for fishes collected with a 4.9-m bottom\ntrawl off Cottonwood Island, Columbia River, 1987-1988.\nThere was one trawling effort at each station during each\nsurvey.\nStation\nTotal no.\nNo./ha,\nTaxa captured (no./ha)\n(depth, m)\ncaptured\ntotal\nSurvey 1 (7-9 Jul 1987)\nCW21 (17)\n5\n48\nPrickly sculpin (10) Cottidae (38)\nCW22 (17)\n7\n76\nCottidae (76)\nCW23 (15)\n14\n176\nWhite sturgeon (13) , prickly\nsculpin (50), Cottidae (113)\nSurvey 2 (19 Nov 1987)\nCW21 (18)\n3\n33\nNorthern squawfish (11), peamouth (11),\nstarry flounder (11)\nCW22 (17)\n2\n20\nWhite sturgeon (10), peamouth (10)\nCW23 (16)\n3\n30\nPeamouth (20), starry flounder (10)\nSurvey 3 (21 Jul 1988)\nCW21 (16)\n9\n99\nSand roller (55), prickly sculpin (11),\nCottidae (33)\nCW22 (17)\n17\n163\nSand roller (19), largescale\nsucker (19), prickly sculpin (10),\nCottidae (115)\nCW23 (15)\n14\n128\nPrickly sculpin (46), Cottidae (82)\nSurvey 4 (6-7 Dec 1988)\nCW21 (16)\n3\n27\nPeamouth (18), Cottidae (9)\nCW22 (16)\n1\n10\nPrickly sculpin (10)\nCW23 (14)\n5\n51\nPrickly sculpin (41) peamouth (10)","14\ncommunity, at least in the short-term. Because of natural\nfluctuations in benthic invertebrate populations, variables other\nthan the groin construction, and the short-term sampling, one\nshould be cautious in attributing any specific observations to\ngroin construction. Ideally, the benthos off Cottonwood Island\nshould have been sampled for several years prior to and several\nyears after the construction of the rock groins to accurately\nassess the effects of construction.\nThe area along Cottonwood Island (RM 68 to 71) is an important\nhabitat for C. salmonis, as evidenced by the relatively high\ndensities. Corophium salmonis is a common benthic invertebrate in\nthe lower Columbia River (McCabe et al. 1989), yet its densities\nare often much lower than the densities reported off Cottonwood\nIsland. Mean densities of C. salmonis at subtidal sampling\nstations between RMs 75 and 79 did not exceed 360/m2 during two\nsurveys, April and September 1988 (McCabe et al. 1989) . Corophium\nsalmonis is particularly important in the lower Columbia River and\nits estuary as food for a variety of fishes, including juvenile\nPacific salmon (Oncorhynchus spp. ) and juvenile white sturgeon\n(McCabe et al. 1983; Kirn et al. 1986; Muir et al. 1988) .\nResults from the November 1987 and December 1988 trawling\nsurveys near Cottonwood Island were consistent with trawling by\nNMFS in the same general area in November 1989 (unpublished data) .\nFish densities in 1989 were relatively low, averaging 34 fish/ha\n(range 11 to 69 fish/ha) ; during the 1987-1988 fall surveys,","15\ndensities were also low, averaging 28 fish/ha (range 20 to\n33 fish/ha) and 29 fish/ha (range 10 to 51 fish/ha), respectively.\nA 7.9-m semiballoon trawl was used in 1989 instead of the 4.9-m\nsemiballoon trawl used in 1987 and 1988. Seven juvenile white\nsturgeon were collected in three trawling efforts in 1989, compared\nto the two captured during the four surveys in 1987 and 1988. Four\nof the sturgeon collected in 1989 were young-of-the-year; one\nyoung-of-the-year sturgeon was collected in November 1987. It\nshould be noted that all NMFS trawling was done during the day.\nFish numbers during darkness could be considerably different than\nduring the day.\nIt appears from NMFS sampling that the installation of rock\ngroins along Cottonwood Island did not adversely affect the benthic\ninvertebrate and demersal fish communities. This sampling\naddressed only short-term effects of rock-groin construction on the\nbenthic invertebrate and demersal fish communities. Additional\nsampling over a period of several years would be needed to\ndetermine long-term changes. Also, this study should be viewed as\na site-specific study. Construction of rock groins at other\nlocations in the Columbia River should be considered and studied on\na site-specific basis.\nThis report does not constitute NMFS' formal comments under\nthe Fish and Wildlife Coordination Act or the National\nEnvironmental Policy Act.","16\nACKNOWLEDGMENTS\nWe thank Lawrence Davis and Maurice Laird for their assistance\nin sampling.","17\nLITERATURE CITED\nCOE (U.S. Army Corps of Engineers)\n1987. Columbia and lower Willamette rivers below Vancouver,\nWashington, and Portland, Oregon: Dobelbower Bar rock\ngroins--design memorandum. U.S. Army Corps of Engineers,\nPortland District. Portland, OR. Various pagination.\nElliott, J. M.\n1977. Some methods for the statistical analysis of samples of\nbenthic invertebrates. Scientific Pub. 25:1-160. Freshwater\nBiol. Assoc., Ferry House, Ambleside, Cumbria, England.\nKirn, R. A., , R. D. Ledgerwood, and A. L. Jensen.\n1986. Diet of subyearling chinook salmon (Oncorhynchus\ntshawytscha) in the Columbia River estuary and changes\neffected by the 1980 eruption of Mount St. Helens. Northw.\nSci. 60 (3) 191-196.\nKrebs, C. J.\n1978. Ecology: the experimental analysis of distribution and\nabundance. Harper and Row. New York, NY. 678 p.\nMcCabe, G. T. Jr., S. A. Hinton, and R. J. McConnell.\n1989. Report D. Pages 167-207 in A. A. Nigro, editor. Status\nand habitat requirements of white sturgeon populations in the\nColumbia River downstream from McNary Dam. Report to\nBonneville Power Administration (Project 86-50) . Portland,\nOR.\nMcCabe, G. T. Jr., W. D. Muir, R. L. Emmett, and J. T. Durkin.\n1983. Interrelationships between juvenile salmonids and\nnonsalmonid fish in the Columbia River estuary. Fish. Bull.,\n81 (4) : 815-826.\nMuir, W. D. , R. L. Emmett, and R. J. McConnell.\n1988. Diet of juvenile and subadult white sturgeon in the\nlower Columbia River and its estuary. Calif. Fish Game\n74 (1) : 49-54.\nPielou, E. L.\n1966. The measurement of diversity in different types of\nbiological collections. J. Theor. Biol. 13:131-144.\nWord, J. Q.\n1976. An evaluation of benthic invertebrate sampling devices\nfor investigating feeding habits of fish. Pages 43-55 in\nC. A. Simenstad and S. J. Lipovsky, editors. Fish food\nhabits studies, 1st Pacific Northwest Technical Workshop.\nUniv. Wash. Sea Grant WSG-WO 77-2. Seattle, WA.","18\nAPPENDIX\nData Tables","Appendix Table 1. --Locations of benthic and bottom trawling stations off\nCottonwood Island, Columbia River, 1987-1988.\nBenthic stations\nStation\nLatitude\nLongitude\nCW11\n46° 05' 28''N.\n122° 54' 59' W.\nCW21\n46° 05' 26''N.\n122° 55' 00''W.\nCW12\n46° 04' 51'N.\n122° 53' 45''W.\nCW22\n46° 04' 50'N.\n122° 53' 48 ' W.\nCW13\n46° 04' 06''N.\n122° 53' 04'W\nCW23\n46° 04' 05''N.\n122° 53' 06''W.\nTrawl stations\nStation\nLatitude\nLongitude\nCW21\n46° 05' 26''N.\n122° 55' 00''W.\nCW22\n46° 04' 50'N.\n122° 53' 48' W.\nCW23\n46° 04' 05''N.\n122° 53' 06''W.","Appendix Table 2. Summaries of benthic invertebrate collections off Cottonwood\nIsland, Columbia River, 1987-1988. Two community structure\nindices -- H' and J' -- were calculated for each station; see\nMethods for descriptions of indices.\nStation: CW11\nDate: 7 Jul 87\nSample size:\n5\nDepth: 3.4 m\nTotal Frequency of\nMean\nStandard\nnumber\nnumber\ndeviation\nTaxon\noccurrence\n(%)\n/m²\n/m²\n15\n60.0\n31.5\n38.6\nOligochaeta\nCorbicula manilensis\n13\n80.0\n27.3\n19.0\nOstracoda\n1\n20.0\n2.1\n4.7\nCorophium salmonis\n521\n100.0\n1,094.1\n1,850.0\nCladocera\n2\n20.0\n4.2\n9.4\nBosmina sp.\n5\n20.0\n10.5\n23.5\n20.0\n4.2\n9.4\nDaphnia sp.\n2\nCalanoida\n16\n60.0\n33.6\n52.7\nCyclopoida\n6\n40.0\n12.6\n18.8\nHarpacticoida\n1\n20.0\n2.1\n4.7\nChironomidae pupae\n3\n20.0\n6.3\n14.0\nHeleidae larvae\n228\n100.0\n478.8\n413.5\nNumber of taxa: 12\nMean number/sample: 162.6\nStandard deviation (SD): 231.9\nMean number/m2:\n1,707.3\nSD/m² : 2,434.6\nH' = 1.43\nJ' = 0.40","Appendix Table 2. --Continued.\nStation: CW21\nDate: 7 Jul 87\nSample size:\n5\nDepth: 8.5 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m2\nOligochaeta\n63\n100.0\n132.3\n86.5\nCorbicula manilensis\n14\n100.0\n29.4\n8.8\nOstracoda\n2\n40.0\n4.2\n5.8\nCorophium salmonis\n845\n80.0\n1,774.5\n1,025.4\nIsopoda\n236\n20.0\n495.6\n1,108.2\nChironomidae pupae\n4\n60.0\n8.4\n8.8\nHeleidae larvae\n329\n100.0\n690.9\n131.0\nNumber of taxa:\n7\nMean number/sample:\n298.6\nStandard deviation (SD) :\n32.3\nMean number/m2: 3,135.3\nSD/m²:\n339.2\nH' =\n1.66\nJ' = 0.59","Appendix Table 2. .--Continued.\nDate: 9 Jul 87\nSample size:\n5\nStation: CW12\nDepth: 5.8 m\nTotal Frequency of\nMean\nStandard\nnumber\nnumber\ndeviation\nTaxon\noccurrence\n(%)\n/m²\n/m²\nNeanthes limnicola\n1\n20.0\n2.1\n4.7\n96\n100.0\n201.6\n96.6\nOligochaeta\nCorbicula manilensis\n16\n100.0\n33.6\n15.6\n1\n20.0\n2.1\n4.7\nOstracoda\nEogammarus confervicolus\n1\n20.0\n2.1\n4.7\nCorophium salmonis\n1,062\n100.0\n2,230.2\n391.9\nChironomidae larvae\n2\n20.0\n4.2\n9.4\nChironomidae pupae\n3\n40.0\n6.3\n9.4\nHeleidae larvae\n350\n100.0\n735.0\n258.4\nNumber of taxa:\n9\nStandard deviation (SD) :\nMean number/sample: 306.4\n68.4\nMean number/m2:\n3,217.2\nSD/m2:\n718.0\nH' = 1.22\nJ' = 0.39","Appendix Table 2.--Continued.\nStation: CW22\nDate: 9 Jul 87\nSample size:\n5\nDepth: 9.8 m\nTotal Frequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nNematoda\n1\n20.0\n2.1\n4.7\nOligochaeta\n18\n40.0\n37.8\n59.7\nCorbicula manilensis\n41\n100.0\n86.1\n51.1\nOstracoda\n6\n60.0\n12.6\n17.2\nCorophium salmonis\n1,281\n100.0\n2,690.1\n1,590.4\nCladocera\n5\n40.0\n10.5\n18.2\nBosmina sp.\n1\n20.0\n2.1\n4.7\nDaphnia sp.\n5\n60.0\n10.5\n10.5\nCalanoida\n3\n40.0\n6.3\n9.4\nChironomidae larvae\n1\n20.0\n2.1\n4.7\nChironomidae pupae\n3\n40.0\n6.3\n9.4\nHeleidae larvae\n341\n100.0\n716.1\n488.0\nNumber of taxa: 12\nMean number/sample:\n341.2\nStandard deviation (SD) :\n198.4\nMean number/m2: 3,582.6\nSD/m2: 2,083.6\nH' =\n1.10\nJ' = 0.31","Appendix Table 2.--Continued.\nStation: CW13\nDate: 9 Jul 87\nSample size:\n5\nDepth: 4.0 m\nTotal\nFrequency of\nMean\nStandard\nnumber\nnumber\ndeviation\nTaxon\noccurrence\n(%)\n/m²\n/m²\nOligochaeta\n27\n100.0\n56.7\n52.3\nCorbicula manilensis\n7\n60.0\n14.7\n15.9\nCorophium salmonis\n378\n100.0\n793.8\n181.0\nChironomidae pupae\n2\n40.0\n4.2\n5.8\nHeleidae larvae\n133\n100.0\n279.3\n113.2\nNumber of taxa:\n5\nMean number/sample:\n109.4\nStandard deviation (SD) :\n21.8\nMean number/m2:\n1,148.7\nSD/m2:\n228.4\nH' = 1.19\nJ' = 0.51","Appendix Table 2.--Continued.\nStation: CW23\nDate: 9 Jul 87\nSample size:\n5\nDepth: 10.4 m\nTotal Frequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nOligochaeta\n8\n40.0\n16.8\n27.4\nCorbicula manilensis\n17\n100.0\n35.7\n17.6\nCorophium salmonis\n238\n100.0\n499.8\n332.8\nChironomidae larvae\n1\n20.0\n2.1\n4.7\nHeleidae larvae\n153\n80.0\n321.3\n283.5\nNumber of taxa:\n5\nMean number/sample:\n83.4\nStandard deviation (SD):\n47.9\nMean number/m2:\n875.7\nSD/m2:\n503.0\nH' = 1.31\nJ' = 0.56","Appendix Table 2. .--Continued.\nDate: 19 Nov 87\nSample size:\n5\nStation: CW11\nDepth: 2.4 m\nTotal\nFrequency of\nMean\nStandard\nnumber\nnumber\ndeviation\nTaxon\noccurrence\n(%)\n/m²\n/m²\n1\n20.0\n2.1\n4.7\nHydra sp.\n27\n80.0\n56.7\n48.5\nOligochaeta\nCorbicula manilensis\n57\n100.0\n119.7\n99.0\nCorophium salmonis\n259\n100.0\n543.9\n284.3\nCladocera\n6\n20.0\n12.6\n28.2\nBosmina sp.\n1\n20.0\n2.1\n4.7\nCalanoida\n1\n20.0\n2.1\n4.7\nHeleidae larvae\n110\n80.0\n231.0\n440.8\nNumber of taxa:\n8\nStandard deviation (SD) :\nMean number/sample:\n92.4\n44.7\nMean number/m2:\n970.2\nSD/m2:\n469.4\nH' = 1.71\nJ' = 0.57","Appendix Table 2.--Continued.\nStation: CW21\nDate: 19 Nov 87\nSample size:\n5\nDepth: 12.8 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nHydra sp.\n1\n20.0\n2.1\n4.7\nOligochaeta\n4\n60.0\n8.4\n8.8\nCorbicula manilensis\n113\n100.0\n237.3\n163.6\nEogammarus confervicolus\n2\n20.0\n4.2\n9.4\nCorophium salmonis\n496\n100.0\n1,041.6\n492.3\nCorophium spinicorne\n38\n60.0\n79.8\n107.2\nHeleidae larvae\n18\n60.0\n37.8\n67.5\nEphemeroptera\n3\n20.0\n6.3\n14.1\nNumber of taxa:\n8\nMean number/sample:\n135.0\nStandard deviation (SD):\n63.1\nMean number/m2: 1,417.5\nSD/m2:\n663.0\nH' =\n1.25\nJ' = 0.42","Appendix Table 2. -- Continued.\nStation: CW12\nDate: 19 Nov 87\nSample size:\n5\nDepth: 1.5 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nOligochaeta\n2\n40.0\n4.2\n5.8\nCorbicula manilensis\n1\n20.0\n2.1\n4.7\nCorophium salmonis\n21\n100.0\n44.1\n53.2\nNumber of taxa:\n3\nMean number/sample:\n4.8\nStandard deviation (SD) :\n5.0\nMean number/m2:\n50.4\nSD/m2:\n52.2\nH' = 0.66\nJ' = 0.42","Appendix Table 2.--Continued.\nStation: CW22\nDate: 19 Nov 87\nSample size:\n5\nDepth: 7.9 m\nTotal Frequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nOligochaeta\n113\n100.0\n237.3\n164.0\nCorbicula manilensis\n21\n100.0\n44.1\n20.2\nEogammarus confervicolus\n1\n20.0\n2.1\n4.7\nCorophium salmonis\n780\n100.0\n1,638.0\n1,247.8\nHeleidae larvae\n32\n100.0\n67.2\n58.7\nNumber of taxa:\n5\nMean number/sample:\n189.4\nStandard deviation (SD):\n99.7\nMean number/m2: 1,988.7\nSD/m2: 1,047.2\nH' = 0.89\nJ' = 0.38","Appendix Table 2.--Continued.\nSample size:\n5\nStation: CW13\nDate: 19 Nov 87\nDepth: 2.7 m\nTotal\nFrequency of\nMean\nStandard\nnumber\nnumber\ndeviation\nTaxon\noccurrence\n(%)\n/m²\n/m²\n19.6\nOligochaeta\n10\n80.0\n21.0\nCorbicula manilensis\n78\n100.0\n163.8\n118.0\nCorophium salmonis\n1,605\n100.0\n3,370.5\n3,115.3\nCalanoida\n1\n20.0\n2.1\n4.7\nChironomidae larvae\n1\n20.0\n2.1\n4.7\nHeleidae larvae\n76\n100.0\n159.6\n170.8\nNumber of taxa:\n6\nStandard deviation (SD) :\nMean number/sample:\n354.2\n317.7\nMean number/m2:\n3,719.1\nSD/m2: 3,336.2\nH' =\n0.58\nJ' = 0.22","Appendix Table 2.--Continued.\nStation: CW23\nDate: 19 Nov 87\nSample size:\n5\nDepth: 9.1 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nOligochaeta\n16\n80.0\n33.6\n29.1\nCorbicula manilensis\n201\n100.0\n422.1\n164.9\nCorophium salmonis\n1,689\n100.0\n3,546.9\n3,925.0\nCorophium spinicorne\n15\n40.0\n31.5\n64.7\nIsopoda\n1\n20.0\n2.1\n4.7\nBosmina sp.\n2\n40.0\n4.2\n5.8\nCalanoida\n2\n40.0\n4.2\n5.8\nCyclopoida\n1\n20.0\n2.1\n4.7\nChironomidae larvae\n12\n40.0\n25.2\n37.6\nHeleidae larvae\n63\n80.0\n132.3\n162.9\nHomoptera\n1\n20.0\n2.1\n4.7\nNumber of taxa: 11\nMean number/sample:\n400.6\nStandard deviation (SD) :\n373.7\nMean number/m2 4,206.3\nSD/m2: 3,924.0\nH' = 0.89\nJ' = 0.26","Appendix Table 2.--Continued.\nStation: CW11\nDate: 21 Jul 88\nSample size:\n5\nDepth: 4. 9 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nNemertea\n2\n20.0\n4.2\n9.4\nNematomorpha\n13\n100.0\n27.3\n12.0\nTurbellaria\n6\n40.0\n12.6\n22.8\nNeanthes limnicola\n5\n40.0\n10.5\n18.2\nOligochaeta\n107\n100.0\n224.7\n118.2\nCorbicula manilensis\n34\n100.0\n71.4\n38.9\nOstracoda\n40\n100.0\n84.0\n59.9\nNeomysis mercedis\n1\n20.0\n2.1\n4.7\nCorophium salmonis\n1,863\n100.0\n3,912.3\n1,830.6\nCorophium spinicorne\n7\n60.0\n14.7\n21.8\nDaphnia sp.\n8\n80.0\n16.8\n20.5\nCyclopoida\n11\n80.0\n23.1\n17.2\nDiptera adults\n1\n20.0\n2.1\n4.7\nChironomidae larvae\n10\n60.0\n21.0\n22.3\nChironomidae pupae\n50\n100.0\n105.0\n53.5\nHeleidae larvae\n430\n100.0\n903.0\n504.7\nOdonata\n2\n40.0\n4.2\n5.8\nEphemeroptera\n1\n20.0\n2.1\n4.7\nHydracarina\n4\n40.0\n8.4\n11.5\nNumber of taxa: 19\nMean number/sample:\n519.0\nStandard deviation (SD) :\n237.6\nMean number/m2:\n5,449.5\nSD/m²: 2,495.2\nH' =\n1.48\nJ' = 0.35","Appendix Table 2. --Continued.\nStation: CW21\nDate: 21 Jul 88\nSample size:\n5\nDepth: 13.4 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nTurbellaria\n3\n40.0\n6.3\n9.4\nOligochaeta\n32\n80.0\n67.2\n50.7\nCorbicula manilensis\n61\n100.0\n128.1\n98.9\nOstracoda\n4\n60.0\n8.4\n8.8\nCorophium spp.\n65\n40.0\n136.5\n195.0\nCorophium salmonis\n1,613\n100.0\n3,387.3\n1,401.4\nCorophium spinicorne\n371\n30.0\n779.1\n1,649.0\nRamellogammarus oregonensis\n18\n40.0\n37.8\n78.8\nDaphnia sp.\n29\n60.0\n60.9\n71.4\nCyclopoida\n6\n40.0\n12.6\n17.2\nDiptera adults\n3\n40.0\n6.3\n9.4\nChironomidae larvae\n6\n40.0\n12.6\n17.2\nChironomidae pupae\n28\n100.0\n58.8\n44.3\nHeleidae larvae\n413\n100.0\n867.3\n291.7\nNumber of taxa: 14\nMean number/sample: 530.4\nStandard deviation (SD)\n249.3\nMean number/m2: 5,569.2\nSD/m2: 2,617.9\nH' = 1.85\nJ' = 0.49","Appendix Table 2. --Continued.\nStation: CW12\nDate: 21 Jul 88\nSample size:\n5\nDepth: 3.7 m\nTotal\nFrequency of\nMean\nStandard\nnumber\ndeviation\nTaxon\nnumber\noccurrence\n(%)\n/m²\n/m²\nNemertea\n1\n20.0\n2.1\n4.7\nNematomorpha\n5\n60.0\n10.5\n12.9\nTurbellaria\n2\n20.0\n4.2\n9.4\nNeanthes limnicola\n4\n20.0\n8.4\n18.8\nOligochaeta\n716\n100.0\n1,503.6\n1,044.3\nCorbicula manilensis\n29\n100.0\n60.9\n31.8\nOstracoda\n1\n20.0\n2.1\n4.7\nNeomysis mercedis\n1\n20.0\n2.1\n4.7\nCorophium salmonis\n1,812\n100.0\n3,805.2\n1,221.1\nCorophium spinicorne\n3\n20.0\n6.3\n14.1\nDaphnia sp.\n9\n60.0\n18.9\n26.1\nCyclopoida\n11\n100.0\n23.1\n11.5\nDiptera adults\n4\n40.0\n8.4\n13.7\nChironomidae larvae\n8\n80.0\n16.8\n15.9\nChironomidae pupae\n22\n100.0\n46.2\n19.1\nHeleidae larvae\n469\n100.0\n984.9\n201.9\nHydracarina\n1\n20.0\n2.1\n4.7\nNumber of taxa: 17\nMean number/sample: 619.6\nStandard deviation (SD) :\n188.4\nMean number/m2:\n6,505.8\nSD/m2: 1,978.2\nH' = 1.61\nJ' = 0.39","Appendix Table 2.--Continued.\nStation: CW22\nDate: 21 Jul 88\nSample size:\n5\nDepth: 14.0 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nNematomorpha\n3\n40.0\n6.3\n9.4\nTurbellaria\n7\n60.0\n14.7\n14.1\nOligochaeta\n225\n100.0\n472.5\n283.2\nCorbicula manilensis\n134\n100.0\n281.4\n151.3\nOstracoda\n1\n20.0\n2.1\n4.7\nCorophium spp.\n5\n20.0\n10.5\n23.5\nCorophium salmonis\n1,006\n100.0\n2,112.6\n890.7\nCorophium spinicorne\n2\n40.0\n4.2\n5.8\nDaphnia sp.\n5\n40.0\n10.5\n14.8\nCyclopoida\n8\n60.0\n16.8\n21.8\nDiptera adults\n1\n20.0\n2.1\n4.7\nChironomidae larvae\n8\n100.0\n16.8\n5.8\nChironomidae pupae\n11\n60.0\n23.1\n28.2\nHeleidae larvae\n382\n100.0\n802.2\n323.3\nArachnida\n2\n40.0\n4.2\n5.8\nNumber of taxa: 15\nMean number/sample:\n360.0\nStandard deviation (SD) :\n130.7\nMean number/m2:\n3,780.0\nSD/m2: 1,372.0\nH' = 1.84\nJ' = 0.47","Appendix Table 2.--Continued.\nSample size:\n5\nStation: CW13\nDate: 21 Jul 88\nDepth: 4.0 m\nTotal\nFrequency of\nMean\nStandard\nnumber\nnumber\ndeviation\nTaxon\noccurrence\n(%)\n/m²\n/m²\n4\n40.0\n8.4\n13.7\nNematomorpha\nNeanthes limnicola\n1\n20.0\n2.1\n4.7\nOligochaeta\n212\n100.0\n445.2\n479.2\nCorbicula manilensis\n38\n100.0\n79.8\n26.4\nCorophium salmonis\n1,181\n100.0\n2,480.1\n1,115.0\nCorophium spinicorne\n7\n80.0\n14.7\n15.9\nDaphnia sp.\n4\n60.0\n8.4\n8.8\nCyclopoida\n3\n60.0\n6.3\n5.8\nDiptera adults\n2\n40.0\n4.2\n5.8\nChironomidae larvae\n64\n60.0\n134.4\n209.7\nChironomidae pupae\n7\n60.0\n14.7\n21.8\nHeleidae larvae\n370\n80.0\n777.0\n505.9\nOdonata\n1\n20.0\n2.1\n4.7\nEphemeroptera\n1\n20.0\n2.1\n4.7\nNumber of taxa: 14\nMean number/sample: 379.0\nStandard deviation (SD):\n175.6\nMean number/m2:\n3,979.5\nSD/m2: 1,843.7\nH' =\n1.66\nJ' = 0.44","Appendix Table 2.--Continued.\nStation: CW23\nDate: 21 Jul 88\nSample size:\n5\nDepth: 12.8 m\nTotal\nFrequency of\nMean\nStandard\nnumber\nnumber\ndeviation\nTaxon\noccurrence\n(%)\n/m²\n/m²\n29.4\n26.1\nNematomorpha\n14\n100.0\nOligochaeta\n131\n100.0\n275.1\n221.2\nCorbicula manilensis\n66\n80.0\n138.6\n98.9\nAmphipoda (Gammaridae)\n1\n20.0\n2.1\n4.7\nCorophium spp.\n11\n60.0\n23.1\n23.9\nCorophium salmonis\n1,128\n100.0\n2,368.8\n726.6\nCorophium spinicorne\n10\n80.0\n21.0\n24.6\nRamellogammarus sp.\n1\n20.0\n2.1\n4.7\nDaphnia sp.\n9\n80.0\n18.9\n11.5\nCyclopoida\n5\n60.0\n10.5\n12.9\nTipulidae larva\n1\n20.0\n2.1\n4.7\nChironomidae larvae\n6\n80.0\n12.6\n11.5\nChironomidae pupae\n9\n100.0\n18.9\n8.8\nHeleidae larvae\n560\n100.0\n1,176.0\n193.2\nHomoptera\n2\n40.0\n4.2\n5.8\nCollembola\n1\n20.0\n2.1\n4.7\nArachnida\n1\n20.0\n2.1\n4.7\nNumber of taxa: 17\nMean number/sample:\n391.2\nStandard deviation (SD) :\n98.4\nMean number/m2:\n4,107.6\nSD/m2: 1,032.6\nH' =\n1.69\nJ' = 0.41","Appendix Table 2.--Continued.\nStation: CW11\nDate: 6 Dec 88\nSample size:\n5\nDepth: 1.8 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nNemertea\n4\n60.0\n8.4\n8.8\nHydra sp.\n3\n40.0\n6.3\n9.4\nTurbellaria\n6\n40.0\n12.6\n18.8\nOligochaeta\n50\n100.0\n105.0\n77.9\nCorbicula manilensis\n44\n100.0\n92.4\n120.0\nOstracoda\n2\n40.0\n4.2\n5.8\nCorophium spp.\n8\n60.0\n16.8\n21.8\nCorophium salmonis\n990\n100.0\n2,079.0\n2,849.6\nCorophium spinicorne\n3\n20.0\n6.3\n14.1\nRamellogammarus oregonensis\n3\n20.0\n6.3\n14.1\nCyclopoida\n1\n20.0\n2.1\n4.7\nDiptera larvae\n1\n20.0\n2.1\n4.7\nChironomidae larvae\n2\n20.0\n4.2\n9.4\nHeleidae larvae\n29\n80.0\n60.9\n75.9\nNumber of taxa: 14\nMean number/sample:\n229.2\nStandard deviation (SD)\n290.7\nMean number/m2:\n2,406.6\nSD/m²: 3,052.0\nH' = 0.93\nJ' = 0.24","Appendix Table 2.--Continued.\nStation: CW21\nDate: 6 Dec 88\nSample size:\n5\nDepth: 13.4 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nNemertea\n15\n100.0\n31.5\n47.0\nNematomorpha\n2\n40.0\n4.2\n5.8\nTurbellaria\n2\n20.0\n4.2\n9.4\nOligochaeta\n17\n100.0\n35.7\n17.6\nCorbicula manilensis\n221\n100.0\n464.1\n339.4\nCorophium spp.\n2\n40.0\n4.2\n5.8\nCorophium salmonis\n63\n100.0\n132.3\n85.8\nCorophium spinicorne\n2\n40.0\n4.2\n5.8\nHeleidae larvae\n65\n100.0\n136.5\n85.6\nNumber of taxa:\n9\nMean number/sample:\n77.8\nStandard deviation (SD) :\n35.9\nMean number/m2:\n816.9\nSD/m2:\n376.5\nH' =\n1.85\nJ' = 0.59","Appendix Table 2.--Continued.\nStation: CW12\nDate: 7 Dec 88\nSample size:\n5\nDepth: 4.3 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nNemertea\n33\n100.0\n69.3\n59.7\nNematomorpha\n3\n60.0\n6.3\n5.8\nHydra sp.\n1\n20.0\n2.1\n4.7\nTurbellaria\n19\n100.0\n39.9\n42.9\nOligochaeta\n153\n100.0\n321.3\n158.8\nCorbicula manilensis\n46\n100.0\n96.6\n59.1\nCorophium spp.\n1\n20.0\n2.1\n4.7\nCorophium salmonis\n410\n100.0\n861.0\n1,004.7\nCorophium spinicorne\n2\n20.0\n4.2\n9.4\nChironomidae larvae\n3\n40.0\n6.3\n9.4\nHeleidae larvae\n50\n100.0\n105.0\n107.8\nNumber of taxa: 11\nMean number/sample:\n144.2\nStandard deviation (SD):\n106.9\nMean number/m2:\n1,514.1\nSD/m²: 1,122.6\nH' = 1.92\nJ' = 0.55","Appendix Table 2.--Continued.\nStation: CW22\nDate: 7 Dec 88\nSample size:\n5\nDepth: 15.2 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nNemertea\n25\n100.0\n52.5\n47.5\nNematomorpha\n1\n20.0\n2.1\n4.7\nHydra sp.\n3\n60.0\n6.3\n5.8\nTurbellaria\n45\n100.0\n94.5\n45.8\nOligochaeta\n325\n100.0\n682.5\n580.8\nCorbicula manilensis\n1,113\n100.0\n2,337.3\n4,358.2\nCorophium salmonis\n13\n60.0\n27.3\n44.3\nCorophium spinicorne\n1\n20.0\n2.1\n4.7\nChironomidae larvae\n1\n20.0\n2.1\n4.7\nHeleidae larvae\n160\n100.0\n336.0\n435.7\nEphemeroptera\n1\n20.0\n2.1\n4.7\nNumber of taxa: 11\nStandard deviation (SD): 401.2\nMean number/sample:\n337.6\nMean number/m2: 3,544.8\nSD/m²: 4,213.2\nH' =\n1.50\nJ' = 0.43","Appendix Table 2. --Continued.\nStation: CW13\nDate: 7 Dec 88\nSample size:\n5\nDepth: 4.3 m\nTotal\nFrequency of\nMean\nStandard\nnumber\nnumber\ndeviation\nTaxon\noccurrence\n/m²\n(%)\n/m²\n10\n80.0\n21.0\n19.6\nNemertea\nNematomorpha\n1\n20.0\n2.1\n4.7\nTurbellaria\n10\n80.0\n21.0\n19.6\nOligochaeta\n126\n100.0\n264.6\n92.3\nCorbicula manilensis\n15\n100.0\n31.5\n19.6\nCorophium salmonis\n170\n100.0\n357.0\n109.6\nCyclopoida\n1\n20.0\n2.1\n4.7\nHeleidae larvae\n106\n100.0\n222.6\n110.2\n20.0\n2.1\n4.7\nLamprey\n1\nNumber of taxa:\n9\nMean number/sample:\n88.0\nStandard deviation (SD) :\n12.6\nMean number/m2:\n924.0\nSD/m²:\n131.8\nH' = 2.02\nJ' = 0.64","Appendix Table 2.--Continued.\nStation: CW23\nDate: 7 Dec 88\nSample size:\n5\nDepth: 13.1 m\nTotal\nFrequency of\nMean\nStandard\nTaxon\nnumber\nnumber\ndeviation\noccurrence\n(%)\n/m²\n/m²\nNemertea\n15\n60.0\n31.5\n44.6\nHydra sp.\n2\n20.0\n4.2\n9.4\nTurbellaria\n10\n20.0\n21.0\n47.0\nOligochaeta\n25\n80.0\n52.5\n94.2\nCorbicula manilensis\n89\n100.0\n186.9\n164.6\nCorophium spp.\n1\n20.0\n2.1\n4.7\nCorophium salmonis\n115\n100.0\n241.5\n232.4\nCorophium spinicorne\n16\n60.0\n33.6\n45.4\nRamellogammarus oregonensis\n2\n20.0\n4.2\n9.4\nChironomidae larvae\n1\n20.0\n2.1\n4.7\nHeleidae larvae\n38\n80.0\n79.8\n114.2\nEphemeroptera\n1\n20.0\n2.1\n4.7\nNumber of taxa: 12\nMean number/sample:\n63.4\nStandard deviation (SD) :\n57.1\nMean number/m2:\n665.7\nSD/m2:\n599.8\nH' =\n2.45\nJ' = 0.68","Appendix Table 3.--Summaries of sediment characteristics off Cottonwood Island, Columbia River, 1987-1988.\nDate : 7 Jul 1987\nSystem : Columbia River\nDate : 19 Nov 1987\nSystem : Columbia River\nProject: Cottonwood Island\nDepth 2.4\nProject: Cottonwood Island\nDepth : 3.4 m\nMethod: 0.1-m2 Van Veen\nStation: CW11\nMethod: 0.1-m2 Van Veen\nStation: CW11\nPercent by size\nU.S.Sieve\nPercent\nPercent\nPercent by size\nU.S.Sieve\nPercent Percent\nclassification\nfiner retained\nclassification\nSize IN\nPan I Phi\nfiner retained\nSize\nPan I\nPhi\n0.0 % Rubble\n0.0 % Rubble\n64 III\n2-1/2 in\n-6\n100.0\n0.0\n64\n2-1/2 in\n-6\n100.0\n0.0\n100.0\n0.0\n0.0 Coarse gravel\n32\n1-1/4 in\n-5\n:\n100.0\n0.0\n0.0 % Coarse gravel\n32 H\n1-1/4 in\n-5\n16\n5/8 in\n-4\n100.0\n0.0\n16\n5/8\nin\n-4\n99.0\n1.0\n3.0 % Medium gravel\n5/16 in -3\n98.0\n2.0\n2.0 % Medium gravel\n8\n5/16\nin\n-3\n97.0\n2.0\n8 IIII\n5\n-2\n85.0\n13.0\n4 mm\nNo.\n5\n-2\n:\n87.0\n10.0\n4 mm\nNo.\n10\n-1\n67.0\n18.0\n31.0 % Fine gravel\n2 mm\n10\n-1\n68.0\n19.0\n29.0 % Fine gravel\n2 mm\n0\n51.0\n16.0\n1 m\n18\n0\n50.0\n18.0\n1 mm\n18\n1\n36.0\n15.0\n31.0 % Coarse sand\n0.5\n35\n1\n33.0\n17.0\n35.0 % Coarse sand\n0.5\n35\n17.0 % Medium sand\n20.0 % Medium sand\n0.25\n60\n2\n16.0\n20.0\n0.25\n60\n2\n16.0\n17.0\n3\n4.0\n12.0\n0.125\n120\n3\n4.0\n12.0\n0.125\n120\n1.0\n3.0\n15.0 % Fine sand\n0.0625\n230\n4\n0.0\n4.0\n16.0 % Fine sand\n0.0625\n230\n4\n0.0 % Silt/clay\n<.0625\n<230\n0.0\n<.0625\n<230\n1.0\n1.0 % Silt/clay\n0.3 % Organics\nGravel =\n32.0 %\n?\n% Organics\nGravel =\n33.0\nSand =\n68.0\nSand =\n66.0\nFines =\n0.0\nFines =\n1.0\nSystem Columbia River\nDate 21 Jul 1988\nSystem : Columbia River\nDate 6 Dec 1988\nProject: Cottonwood Island\nDepth 4.9\nProject: Cottonwood Island\nDepth 1.3m\nStation: CW11\nMethod: 0.1-m2 Van Veen\nStation: CW11\nMethod: 0.1-m2 Van Veen\nU.S.Sieve\nPercent Percent\nPercent by size\nU.S.Sieve\nPercent\nPercent\nPercent by size\nPan I\nSize\nPhi\nfiner retained\nclassification\nSize\nPan I\nPhi\nfiner retained\nclassification\n64\n2-1/2 in\n-6\n:\n100.0\n0.0\n0.0 1 Rubble\n64 IN\n2-1/2 in\n-6\n:\n100.0\n0.0\n0.0 % Rubble\n32\n1-1/4 in\n-5\n:\n100.0\n0.0\n0.0 Coarse gravel\n32\n1-1/4 in\n-5\n0.0 Coarse gravel\n:\n100.0\n0.0\nI\n16\n5/8\nin\n-4\n96.0\n4.0\n16\n5/8 in\n-4\n:\n99.0\n1.0\n8\n5/16\nin\n-3\n:\n93.0\n3.0\n7.0 % Medium gravel\n8 mm\n5/16 in\n-3\n:\n96.7\n2.3\n3.3 % Medium gravel\n4 mm\nNo.\n5\n-2\n84.0\n9.0\n4 III\nNo.\n5\n-2\n84.8\n11.9\n2 mm\n10\n-1\n72.0\n12.0\n21.0 f Fine gravel\n2 mm\n10\n-1\n70.9\n13.9\n25.8 % Fine gravel\n1\n18\n0\n56.0\n16.0\n1 m\n18\n0\n61.4\n9.5\n0.5\n35\n1\n38.0\n18.0\n34.0 % Coarse sand\n0.5 m\n35\n1\n51.3\n10.1\n19.6 % Coarse sand\n0.25\n60\n2\n24.0\n14.0\n14.0 % Medium sand\n0.25\n60\n2\n34.0\n17.3\n17.3 % Medium sand\n0.125\n120\n3\n10.0\n14.0\n0.125\n120\n3\n8.7\n25.3\n0.0625\n230\n4\n1.0\n9.0\n23.0 f Fine sand\n0.0625\n230\n4\n1.3\n7.4\n32.7 % Fine sand\n<.0625\n<230\n1.0\n1.0 % Silt/clay\n<.0625\n<230\n1.3\n1.3 % Silt/clay\nGravel =\n28.0\n?\nof Organics\nGravel =\n29.1\n0.6 % Organics\nSand =\n71.0\nSand =\n69.6 %\nFines =\n1.0\nFines\n1.3%","Appendix Table 3.--Continued.\nSystem Columbia River\nDate 7 Jul 1987\nSystem Columbia River\nDate 19 Nov 1987\nProject: Cottonwood Island\nDepth 8.5\nProject: Cottonwood Island\nDepth\n12.8\nStation: CW21\nMethod: 0.1-m2 Van Veen\nStation: CW21\nMethod: 0.1-m2 Van Veen\nU.S. Sieve\nPercent Percent\nPercent by size\nU.S. Sieve\nPercent Percent\nPercent by size\nSize mm\nPan #\nPhi\nfiner retained\nclassification\nSize mm\nPan I\nPhi\nfiner retained\nclassification\n64 mm\n2-1/2 in -6\n100.0\n0.0\n0.0 % Rubble\n64 IMM\n2-1/2 in\n-6\n100.0\n0.0\n0.0 Rubble\n32\n1-1/4 in\n-5\n100.0\n0.0\n0.0 Coarse gravel\n32 IN\n1-1/4 in\n-5\n82.0\n18.0\n18.0 Coarse gravel\n16\n5/8 in\n-4\n98.0\n2.0\n16\n5/8 in\n-4\n71.0\n11.0\n8\n5/16 in\n-3\n93.0\n5.0\n7.0 % Medium gravel\n8 mm\n5/16 in\n-3\n61.0\n10.0\n21.0 % Medium gravel\n4 mm\nNo.\n5\n-2\n72.0\n21.0\n4 mm\nNo.\n5\n-2\n52.0\n9.0\n2\n10 -1\n47.0\n25.0\n46.0 % Fine gravel\n2 mm\n10\n-1\n43.0\n9.0\n18.0 % Fine gravel\n1\n18\n0\n28.0\n19.0\n1 mm\n18\n0\n33.0\n10.0\n0.5\n35\n1\n16.0\n12.0\n31.0 t Coarse sand\n0.5\n35\n1\n26.0\n7.0\n17.0 % Coarse sand\n0.25\n60\n2\n8.0\n8.0\n8.0 % Medium sand\n0.25 m\n60\n2\n16.0\n10.0\n10.0 % Medium sand\n0.125\n120\n3\n1.0\n7.0\n0.125 III\n120\n3\n4.0\n12.0\n0.0625\n230\n4\n0.0\n1.0\n8.0 % Fine sand\n0.0625 In\n230\n4\n2.0\n2.0\n14.0 % Fine sand\n<.0625\n<230\n0.0\n0.0 % Silt/clay\n<.0625\n<230\n2.0\n2.0 % Silt/clay\nGravel =\n53.0\n?\nf Organics\nGravel =\n57.0\n0.4 Organics\nSand =\n47.0\nSand =\n41.0\nFines =\n0.0\nFines =\n2.0\nSystem Columbia River\nDate 21 Jul 1988\nSystem : Columbia River\nDate 6 Dec 1988\nProject: Cottonwood Island\nDepth 13.4\nProject: Cottonwood Island\nDepth\n13.4\nStation: CW21\nMethod: 0.1-m2 Van Veen\nStation: CW21\nMethod: 0.1-m2 Van Veen\nU.S.Sieve\nPercent Percent\nPercent by size\nU.S. Sieve\nPercent Percent Percent by size\nSize\nPan I\nPhi\nfiner retained\nclassification\nSize IIII\nPan #\nPhi\nfiner retained\nclassification\n64 2-1/2 in -6\n100.0\n0.0\n0.0 Rubble\n64 IIIII\n2-1/2 in\n-6\n100.0\n0.0\n0.0 Rubble\n32 I\n1-1/4 in -5\n92.0\n8.0\n8.0 Coarse gravel\n32 IN\n1-1/4 in\n-5\n100.0\n0.0\n0.0 % Coarse gravel\n16\n5/8\nin\n-4\n86.0\n6.0\n16 IN\n5/8 in\n-4\n99.6\n0.4\n8\n5/16 in -3\n74.0\n12.0\n18.0 f Medium gravel\n8 mm\n5/16 in\n-3\n99.1\n0.5\n0.9 % Medium gravel\n4\nNo.\n5\n-2\n64.0\n10.0\n4 mm\nNo.\n5\n-2\n:\n90.6\n8.5\n2\n10 -1\n56.0\n8.0\n18.0 % Fine gravel\n2 mm\n10\n-1\n69.3\n21.3\n29.8 % Fine gravel\n1 mm\n18\n0\n43.0\n13.0\n1 mm\n18\n0\n54.9\n14.4\n0.5\n35\n1\n31.0\n12.0\n25.0 f Coarse sand\n0.5 NET\n35\n1\n41.1\n13.8\n28.2 f Coarse sand\n0.25\n60\n2\n16.0\n15.0\n15.0 f Medium sand\n0.25 mm\n60\n2\n14.2\n26.9\n26.9 % Medium sand\n0.125\n120\n3\n1.0\n15.0\n0.125 mm\n120\n3\n6.5\n7.7\n0.0625\n230\n4\n0.0\n1.0\n16.0 q Fine sand\n0.0625 III\n230\n4\n2.2\n4.3\n12.0 % Fine sand\n<.0625\n<230\n0.0\n0.0 % Silt/clay\n<.0625\n<230\n2.2\n2.2 q Silt/clay\nGravel =\n44.0\n0.3 % Organics\nGravel =\n30.7\n0.3 % Organics\nSand =\n56.0\nSand =\n67.1\nFines\n0.0 %\nFines =\n2.2 %","Appendix Table 3.--Continued.\nSystem : Columbia River\nDate 9 Jul 1987\nSystem : Columbia River\nDate : 19 Nov 1987\nProject: Cottonwood Island\nDepth 5.8\nProject: Cottonwood Island\nDepth 1.5\nStation: CW12\nMethod: 0.1-m2 Van Veen\nStation: CW12\nMethod: 0.1-m2 Van Veen\nU.S. Sieve\nPercent Percent\nPercent by size\nU.S. Sieve\nPercent Percent\nPercent by size\nfiner retained\nclassification\nSize\nPan I\nPhi\nSize mm\nPan I\nPhi\nfiner retained\nclassification\n64\n2-1/2 in\n-6\n100.0\n0.0\n0.0 Rubble\n64 IIIIII\n2-1/2 in\n-6\n100.0\n0.0\n0.0 % Rubble\n1-1/4 in\n32\n1-1/4\nin\n-5\n100.0\n0.0\n0.0 Coarse gravel\n32 IIII\n-5\n100.0\n0.0\n0.0 of Coarse gravel\nIIII\n16 IIIII\n5/8\nin\n5/8 in\n-4\n100.0\n0.0\n16 MM\n-4\n100.0\n0.0\n8\n5/16 in -3\n99.0\n1.0\n1.0 % Medium gravel\n8 IIII\n5/16 in\n-3\n100.0\n0.0\n0.0 % Medium gravel\n4 mm\nNo.\n5\n-2\n96.0\n3.0\n4 IIII\nNo.\n5\n-2\n99.0\n1.0\n2\n10 -1\n83.0\n13.0\n16.0 % Fine gravel\n2 mm\n10\n-1\n94.0\n5.0\n6.0 % Fine gravel\n1 mm\n18\n0\n63.0\n20.0\n18\n0\n77.0\n17.0\nMEN\n0.5\n35\n1\n44.0\n19.0\n39.0 % Coarse sand\n0.5\n35\n1\n43.0\n34.0\n51.0 % Coarse sand\n0.25\n60\n2\n22.0\n22.0\n22.0 % Medium sand\n0.25\n60\n2\n:\n11.0\n32.0\n32.0 % Medium sand\n0.125\n120\n3\n10.0\n12.0\n0.125 mm\n120\n3\n:\n2.0\n9.0\n0.0625\n230\n4\n1.0\n9.0\n21.0 % Fine sand\n0.0625 ITEM\n230\n4\n:\n0.0\n2.0\n11.0 % Fine sand\n<.0625\n<230\n1.0\n1.0 % Silt/clay\n<.0625\n<230\n0.0\n0.0 % Silt/clay\nGravel =\n17.0\n?\n% Organics\nGravel =\n6.0 %\n0.3 % Organics\nSand =\n82.0\nSand =\n94.0\nFines =\n1.0\nFines =\n0.0 %\nSystem : Columbia River\nDate : 21 Jul 1988\nSystem : Columbia River\nDate : 7 Dec 1988\nProject: Cottonwood Island\nDepth 3.7\nProject: Cottonwood Island\nDepth 4.3 m\nStation: CN12\nMethod: 0.1-m2 Van Veen\nStation: CW12\nMethod: 0.1-m2 Van Veen\nU.S.Sieve\nPercent\nPercent\nPercent by size\nSieve\nPercent\nPercent\nPercent by size\nSize IIII\nPan I\nPhi\nfiner retained\nclassification\nSize\nPan I\nPhi\nfiner retained\nclassification\n64 I\n2-1/2 in -6\n100.0\n0.0\n0.0 & Rubble\n64 THE\n2-1/2 in\n-6\n100.0\n0.0\n0.0 % Rubble\n32\n1-1/4 in\n-5\n:\n100.0\n0.0\n0.0 1 Coarse gravel\n32\n1-1/4 in\n-5\n98.0\n2.0\n2.0 % Coarse gravel\nI\nmm\n16\n5/8\nin\n-4\n:\n100.0\n0.0\n16 mm\n5/8 in\n-4\n98.0\n0.0\n8\n5/16\n-3\n:\n100.0\n0.0\n0.0 % Medium gravel\n8 mm\n5/16 in\n-3\n98.0\n0.0\n0.0 % Medium gravel\n4 mm\nNo.\n5\n-2\n97.0\n3.0\n4 mm\nNo.\n5\n-2\n96.4\n1.6\n2 mm\n10 -1\n91.0\n6.0\n9.0 f Fine gravel\n2 mm\n10\n-1\n90.1\n6.3\n7.9 % Fine gravel\n1 mm\n18\n0\n78.0\n13.0\n1 mm\n18\n0\n83.1\n7.0\n0.5\n35\n1\n55.0\n23.0\n36.0 % Coarse sand\n0.5\n35\n1\n66.6\n16.5\n23.5 % Coarse sand\n0.25 mm\n60\n2\n1.0\n54.0\n54.0 % Medium sand\n0.25\n60\n2\n50.3\n16.3\n16.3 % Medium sand\n0.125 IN\n120\n3\n0.0\n1.0\n0.125\n120\n3\n6.6\n43.7\n0.0625 m\n230\n4\n0.0\n0.0\n1.0 of Fine sand\n0.0625\n230\n4\n1.1\n5.5\n49.2 % Fine sand\n<.0625\n<230\n0.0\n0.0 % Silt/clay\n<.0625\n<230\n1.1\n1.1 % Silt/clay\nGravel =\n9.0\n0.3 % Organics\nGravel =\n9.9\n0.4 Organics\nSand =\n91.0\nSand =\n89.0\nFines\n0.0\nFines\n1.1%","Appendix Table 3.--Continued.\nSystem : Columbia River\nDate : 9 Jul 1987\nSystem : Columbia River\nDate : 19 Nov 1987\nProject: Cottonwood Island\nDepth 9.8 m\nProject: Cottonwood Island\nDepth : 7.9\nStation: CW22\nMethod: 0.1-m2 Van Veen\nStation: CW22\nMethod: 0.1-m2 Van Veen\nU.S. Sieve\nPercent Percent\nPercent by size\nU.S. Sieve\nPercent Percent\nPercent by size\nSize\nPan #\nPhi\nfiner retained\nclassification\nSize mm\nPan #\nPhi\nfiner retained\nclassification\n64 mm 2-1/2 in -6\n100.0\n0.0\n0.0 % Rubble\n64\n2-1/2 in\n-6\n100.0\n0.0\n0.0 % Rubble\nmm\n32 IIII\n1-1/4 in\n-5\n100.0\n0.0\n0.0 Coarse gravel\n32 IIIII\n1-1/4 in\n-5\n100.0\n0.0\n0.0 % Coarse gravel\n16 III\n5/8 in -4\n5/8 in\n:\n99.0\n1.0\n16\n-4\n100.0\n0.0\n8 IN\n5/16 in\n-3\n99.0\n0.0\n1.0 % Medium gravel\n8 mm\n5/16 in\n-3\n100.0\n0.0\n0.0 % Medium gravel\n4 TOE\nNo.\n5\n-2\n98.0\n1.0\n4 mm\nNo.\n5\n-2\n97.0\n3.0\n2 IN\n10\n-1\n97.0\n1.0\n2.0 % Fine gravel\n2 mm\n10\n-1\n87.0\n10.0\n13.0 % Fine gravel\n1 mm\n18\n0\n91.0\n6.0\n1 mm\n18\n0\n72.0\n15.0\n0.5 mm\n35\n1\n78.0\n13.0\n19.0 % Coarse sand\n0.5\n35\n1\n45.0\n27.0\n42.0 % Coarse sand\n0.25\n60\n2\n61.0\n17.0\n17.0 % Medium sand\n0.25\n60\n2\n15.0\n30.0\n30.0 % Medium sand\n0.125 III\n120\n3\n15.0\n46.0\n0.125\n120\n3\n5.0\n10.0\n0.0625\n230\n4\n1.0\n14.0\n60.0 % Fine sand\n0.0625\n230\n4\n1.0\n4.0\n14.0 % Fine sand\n<.0625\n<230\n1.0\n1.0 % Silt/clay\n<.0625\n<230\n1.0\n1.0 % Silt/clay\nGravel =\n3.0\n?\nf Organics\nGravel =\n13.0 %\n0.4 % Organics\nSand\n96.0 %\nSand =\n86.0\nFines\n1.0%\nFines =\n1.0\nSystem Columbia River\nDate : 21 Jul 1988\nSystem : Columbia River\nDate : 7 Dec 1988\nProject: Cottonwood Island\nDepth 14.0 m\nProject: Cottonwood Island\nDepth : 15.2 m\nStation: CW22\nMethod: 0.1-m2 Van Veen\nStation: CW22\nMethod: 0.1-m2 Van Veen\nU.S. Sieve\nPercent Percent\nPercent by size\nU.S. Sieve\nPercent Percent\nPercent by size\nSize IIII\nPan I\nPhi\nfiner retained\nclassification\nPan I\nSize III\nPhi\nfiner retained\nclassification\n64 III 2-1/2 in -6\n100.0\n0.0\n0.0 % Rubble\n64 mm\n2-1/2 in\n-6\n100.0\n0.0\n0.0 % Rubble\n32 IN\n1-1/4 in\n-5\n100.0\n0.0\n0.0 % Coarse gravel\n32 mm\n1-1/4 in\n-5\n100.0\n0.0\n0.0 % Coarse gravel\n16 -\n5/8 in -4\n100.0\n0.0\n16 mm\n5/8 in\n-4\n:\n100.0\n0.0\n8 IIII\n5/16 in -3\n99.0\n1.0\n1.0 % Medium gravel\n8 mm\n5/16 in\n-3\n99.8\n0.2\n0.2 % Medium gravel\n4\nNo.\n5\n-2\n:\n97.0\n2.0\n4 mm\nNo.\n5\n-2\n98.6\n:\n1.2\n2 mm\n10 -1\n89.0\n8.0\n10.0 % Fine gravel\n2 mm\n10\n-1\n90.3\n8.3\n9.5 % Fine gravel\n1 mm\n18\n0\n72.0\n17.0\n1 mm\n18\n0\n70.9\n19.4\n0.5 mm\n35\n1\n42.0\n30.0\n47.0 1 Coarse sand\n0.5\n35\n1\n46.1\n24.8\n44.2 % Coarse sand\n0.25 TOWN\n60\n2\n16.0\n26.0\n26.0 % Medium sand\n0.25 TOWN\n60\n2\n20.1\n26.0\n26.0 % Medium sand\n0.125 IN\n120\n3\n3.0\n13.0\n0.125 mm\n120\n3\n1.0\n19.1\n0.0625 III\n230\n4\n1.0\n2.0\n15.0 % Fine sand\n0.0625\n230\n4\n0.2\n0.8\n19.9 % Fine sand\n<.0625\n<230\n1.0\n1.0 f Silt/clay\n<.0625\n<230\n0.2\n0.2 % Silt/clay\nGravel =\n11.0 f\n0.4 f Organics\nGravel =\n9.7\n0.3 % Organics\nSand =\n88.0 f\nSand =\n90.1\nFines =\n1.0%\nFines\n0.2","Appendix Table 3.--Continued.\nDate : 19 Nov 1987\nSystem : Columbia River\nDate 9 Jul 1987\nSystem : Columbia River\nProject: Cottonwood Island\nDepth : 2.7\nProject: Cottonwood Island\nDepth : 4.0 m\nStation: CW13\nMethod: 0.1-m2 Van Veen\nStation: CW13\nMethod: 0.1-m2 Van Veen\nU.S.Sieve\nPercent Percent\nPercent by size\nU.S.Sieve\nPercent Percent\nPercent by size\nfiner retained classification\nSize III\nPan #\nPhi\nfiner retained classification\nSize\nPan I\nPhi\n0.0 % Rubble\n0.0 % Rubble\n64\n2-1/2 in -6\n100.0\n0.0\n64\n2-1/2 in\n-6\n:\n100.0\n0.0\n1-1/4 in\n100.0\n0.0\n0.0 Coarse gravel\n32\n1-1/4 in\n-5\n100.0\n:\n0.0\n0.0 f Coarse gravel\n32 IN\n-5\n5/8 in\n-4\n99.0\n1.0\n16\n5/8\nin\n-4\n:\n100.0\n0.0\n16 -\n8 mm\n5/16\nin\n-3\n0.0 % Medium gravel\n8 III\n5/16 in -3\n98.0\n1.0\n2.0 % Medium gravel\n:\n100.0\n0.0\n4 mm\nNo.\n5\n-2\n99.0\n1.0\n4 IN\nNo. 5 -2\n96.0\n2.0\n10 -1\n90.0\n6.0\n8.0 % Fine gravel\n2 mm\n10\n-1\n98.0\n1.0\n2.0 % Fine gravel\n2 mm\n1 mm\n0\n82.0\n8.0\n1\n18\n0\n95.0\n3.0\n18\n0.5\n35\n1\n84.0\n11.0\n14.0 % Coarse sand\n0.5 mm\n35\n1\n69.0\n13.0\n21.0 % Coarse sand\n60\n2\n30.0\n39.0\n39.0 % Medium sand\n0.25\n60\n2\n37.0\n47.0\n47.0 % Medium sand\n0.25\n120\n0.125\n120\n3\n2.0\n35.0\n0.125\n3\n2.0\n28.0\n37.0 q Fine sand\n230\n0.0625\n230\n4\n0.0\n2.0\n0.0625\n4\n0.0\n2.0\n30.0 % Fine sand\n0.0 q Silt/clay\n0.0\n0.0 % Silt/clay\n<.0625\n<230\n0.0\n<.0625\n<230\nGravel =\n2.0\n?\nf Organics\nGravel =\n10.0\n0.5 % Organics\nSand =\nSand =\n90.0\n98.0 1\nFines =\n0.0\nf\nFines =\n0.0 f\nSystem : Columbia River\nDate 21 Jul 1988\nSystem : Columbia River\nDate : 7 Dec 1988\nProject: Cottonwood Island\nDepth 4.0 m\nProject: Cottonwood Island\nDepth 4.3 m\nMethod: 0.1-m2 Van Veen\nStation: CW13\nMethod: 0.1-m2 Van Veen\nStation: CW13\nU.S. Sieve\nPercent Percent\nPercent by size\nSieve\nPercent Percent\nPercent by size\nSize TOWA\nPan I\nPhi\nfiner retained\nclassification\nSize IIII\nPan I\nPhi\nfiner retained\nclassification\n0.0 of Rubble\n64\n2-1/2 in\n-6\n:\n100.0\n0.0\n0.0 % Rubble\n64 m 2-1/2 in -6\n100.0\n0.0\n32\n1-1/4 in\n-5\n:\n100.0\n0.0\n0.0 % Coarse gravel\n32 m\n1-1/4 in\n-5\n100.0\n0.0\n0.0 Coarse gravel\n16\n5/8\nin\n-4\n5/8 in -4\n:\n100.0\n0.0\n16 IN\n:\n100.0\n0.0\n8 m\n5/16\nin\n-3\n:\n100.0\n0.0\n0.0 f Medium gravel\n8 mm\n5/16 in -3\n99.6\n0.4\n0.4 % Medium gravel\n4 mm\nNo.\n5\n-2\n99.0\n1.0\n4 mm\nNo.\n5\n-2\n98.4\n1.2\n2 mm\n10\n-1\n96.0\n3.0\n4.0 f Fine gravel\n2 m\n10 -1\n95.7\n2.7\n3.9 % Fine gravel\n1\n18\n0\n89.0\n7.0\n1 mm\n18\n0\n91.8\n3.9\n0.5\n35\n1\n65.0\n24.0\n31.0 % Coarse sand\n0.5 mm\n35\n1\n81.7\n10.1\n14.0 % Coarse sand\n0.25\n60\n2\n12.0\n53.0\n53.0 % Medium sand\n0.25\n60\n2\n39.0\n42.7\n42.7 % Medium sand\n0.125\n120\n3\n2.0\n10.0\n0.125 m\n120\n3\n2.7\n36.3\n0.0625\n230\n4\n0.0\n2.0\n12.0 % Fine sand\n0.0625\n230\n4\n0.4\n2.3\n38.6 % Fine sand\n<.0625\n<230\n0.0\n0.0 f Silt/clay\n<.0625\n<230\n0.4\n0.4 % Silt/clay\nGravel =\n4.0 f\n0.6 f Organics\nGravel =\n4.3\n0.5 % Organics\nSand =\n96.0 f\nSand =\n95.3\nFines :\n0.0\nFines =\n0.4%","Appendix Table 3.--Continued.\nSystem : Columbia River\nDate I Jul 1987\nSystem : Columbia River\nDate : 19 Nov 1987\nProject: Cottonwood Island\nDepth 10.4 m\nProject: Cottonwood Island\nDepth 9.1 n\nStation: CW23\nMethod: 0.1-m2 Van Veen\nStation: CW23\nMethod: 0.1-m2 Van Veen\nU.S. Sieve\nPercent Percent\nPercent by size\nU.S. Sieve\nPercent Percent\nPercent by size\nSize\nPan I\nPhi\nfiner retained\nclassification\nSize H\nPan I\nPhi\nfiner retained\nclassification\n64 IIII\n2-1/2 in -6\n100.0\n0.0\n0.0 % Rubble\n64 m\n2-1/2 in\n-6\n100.0\n0.0\n0.0 % Rubble\n32 I\n1-1/4 in -5\n97.0\n3.0\n3.0 q Coarse gravel\n32 IIIII\n1-1/4 in\n-5\n100.0\n0.0\n0.0 % Coarse gravel\n16\n5/8\nin\n-4\n:\n89.0\n8.0\n16 FEE\n5/8 in\n-4\n73.0\n27.0\n8\n5/16 in\n-3\n79.0\n10.0\n18.0 % Medium gravel\n5/16 in\n8 mm\n-3\n60.0\n13.0\n40.0 % Medium gravel\n4 IIII\nNo.\n5\n-2\n72.0\n7.0\n4 mm\nNo.\n5\n-2\n50.0\n10.0\n2 mm\n10 -1\n67.0\n5.0\n12.0 f Fine gravel\n2 mm\n10\n-1\n41.0\n9.0\n19.0 % Fine gravel\n1 mm\n18\n0\n62.0\n5.0\n1 mm\n18\n0\n35.0\n6.0\n0.5\n35\n1\n53.0\n9.0\n14.0 f Coarse sand\n0.5 TEL\n35\n1\n31.0\n4.0\n10.0 % Coarse sand\n0.25\n60\n2\n20.0\n33.0\n33.0 % Medium sand\n0.25 IN\n60\n2\n14.0\n17.0\n17.0 % Medium sand\n0.125\n120\n3\n3.0\n17.0\n0.125 III\n120\n3\n1.0\n13.0\n0.0625\n230\n4\n0.0\n3.0\n20.0 % Fine sand\n0.0625 H\n230\n4\n0.0\n1.0\n14.0 % Fine sand\n<.0625\n<230\n0.0\n0.0 f Silt/clay\n<.0625 TEX\n<230\n0.0\n0.0 % silt/clay\nGravel =\n33.0 q\n?\n% Organics\nGravel =\n59.0 %\n0.5 % Organics\nSand =\n67.0\nSand =\n41.0 %\nFines =\n0.0\nFines =\n0.0\nSystem Columbia River\nDate 21 Jul 1988\nSystem : Columbia River\nDate 7 Dec 1988\nProject: Cottonwood Island\nDepth : 12.8 n\nProject: Cottonwood Island\nDepth\n13.1\nm\nStation: CW23\nMethod: 0.1-m2 Van Veen\nStation: CW23\nMethod: 0.1-m2 Van Veen\nU.S. Sieve\nPercent Percent\nPercent by size\nU.S. Sieve\nPercent Percent\nPercent by size\nSize mm\nPan I\nPhi\nfiner retained\nclassification\nSize FUND\nPan I\nPhi\nfiner retained\nclassification\n64 2-1/2 in -6\n100.0\n0.0\n0.0 of Rubble\n64 m\n2-1/2 in\n-6\n100.0\n0.0\n0.0 % Rubble\n32\n1-1/4 in -5\n89.0\n11.0\n11.0 1 Coarse gravel\n32 1\n1-1/4 in\n-5\n100.0\n0.0\n0.0 % Coarse gravel\n16\n5/8 in -4\n73.0\n16.0\n16 IN\n5/8 in\n-4\n:\n70.8\n29.2\n8\n5/16 in -3\n64.0\n9.0\n25.0 % Medium gravel\n8 mm\n5/16 in\n-3\n43.3\n27.5\n56.7 % Medium gravel\n4\nNo.\n5\n-2\n59.0\n5.0\n4 mm\nNo.\n5\n-2\n:\n33.7\n9.6\n2\n10 -1\n53.0\n6.0\n11.0 % Fine gravel\n2 mm\n10\n-1\n31.1\n2.6\n12.2 % Fine gravel\n1 mm\n18\n0\n48.0\n5.0\n1 mm\n18\n0\n28.4\n2.7\n0.5\n35\n1\n38.0\n10.0\n15.0 f Coarse sand\n0.5 IN\n35\n1\n18.0\n10.4\n13.1 % Coarse sand\n0.25\n60\n2\n9.0\n29.0\n29.0 of Medium sand\n0.25 mm\n60\n2\n6.7\n11.3\n11.3 % Medium sand\n0.125 m\n120\n3\n1.0\n8.0\n0.125 IN\n120\n3\n0.4\n6.3\n0.0625\n230\n4\n0.0\n1.0\n9.0 % Fine sand\n0.0625 mm\n230\n4\n0.0\n0.4\n6.7 % Fine sand\n<.0625\n<230\n0.0\n0.0 % Silt/clay\n<.0625 IN\n<230\n0.0\n0.0 % Silt/clay\nGravel =\n47.0 %\n0.5 % Organics\nGravel =\n68.9\n0.6 of Organics\nSand =\n53.0\nSand =\n31.1\nFines =\n0.0\nFines =\n0.0","Appendix Table 4. Summaries of fish catches off Cottonwood Island, Columbia\nRiver, 1987-1988. Two community structure indices -- H' and\nJ' -- were calculated for each trawling effort (see Methods\nfor descriptions of indices). .\nSTATION: CW21\nGear: 4.9-m Trawl\nDate: 9 Jul 1987\nTime: 1312 h\nDepth: 17.4 m\nDistance traveled: 315 m\nNo./ha\nNo.\nSpecies\ncaptured\nPrickly sculpin\n1\n10\nUnidentified Cottidae\n4\n38\n5\n48\nTOTAL\nH' = 0.72\nJ' = 0.72\nSTATION: CW22\nGear: 4.9-m Trawl\nDate: 9 Jul 1987\nTime: 1244 h\nDepth: 17.4 m\nDistance traveled: 278 m\nNo.\nNo./ha\nSpecies\ncaptured\nUnidentified Cottidae\n7\n76\n7\n76\nTOTAL\nH' = 0.00\nJ' = 1.00","Appendix Table 4. --Continued.\nSTATION: CW23\nGear: 4.9-m Trawl\nDate: 9 Jul 1987\nTime: 1215 h\nDepth: 14.9 m\nDistance traveled: 241 m\nNo.\nNo./ha\nSpecies\ncaptured\nWhite sturgeon\n1\n13\nPrickly sculpin\n4\n50\nUnidentified Cottidae\n9\n113\nTOTAL\n14\n176\nH' = 1.20\nJ' = 0.76\nSTATION: CW21\nGear: 4.9-m Trawl\nDate: 19 Nov 1987\nTime: 0815 h\nDepth: 18.0 m\nDistance traveled: 278 m\nNo.\nNo./ha\nSpecies\ncaptured\nNorthern squawfish\n1\n11\nStarry flounder\n1\n11\nPeamouth\n1\n11\nTOTAL\n3\n33\nH' = 1.58\nJ' = 1.00","Appendix Table 4. .--Continued.\nSTATION: CW22\nGear: 4.9-m Trawl\nDate: 19 Nov 1987\nTime: 0901 h\nDepth: 16.8 m\nDistance traveled: 296 m\nNo.\nNo./ha\nSpecies\ncaptured\nWhite sturgeon\n1\n10\nPeamouth\n1\n10\n2\n20\nTOTAL\nH' = 1.00\nJ' = 1.00\nSTATION: CW23\nGear: 4.9-m Trawl\nDate: 19 Nov 1987\nTime: 0931 h\nDepth: 15.5 m\nDistance traveled: 296 m\nNo.\nNo./ha\nSpecies\ncaptured\nPeamouth\n2\n20\nStarry flounder\n1\n10\nTOTAL\n3\n30\nH' = 0.92\nJ' = 0.92","Appendix Table 4.--Continued.\nSTATION: CW21\nGear: 4.9-m Trawl\nDate: 21 Jul 1988\nTime: 1611 h\nDepth: 16.2 m\nDistance traveled: 278 m\nNo.\nNo./ha\nSpecies\ncaptured\nSand roller\n5\n55\nPrickly sculpin\n1\n11\nUnidentified Cottidae\n3\n33\nTOTAL\n9\n99\nH' = 1.35\nJ' = 0.85\nSTATION: CW22\nGear: 4.9-m Trawl\nDate: 21 Jul 1988\nTime: 1544 h\nDepth: 17.4 m\nDistance traveled: 315 m\nNo.\nNo./ha\nSpecies\ncaptured\nSand roller\n2\n19\nLargescale sucker\n2\n19\nPrickly sculpin\n1\n10\nUnidentified Cottidae\n12\n115\nTOTAL\n17\n163\nH' = 1.32\nJ' = 0.66","Appendix Table 4.--Continued.\nSTATION: CW23\nGear: 4.9-m Trawl\nDate: 21 Jul 1988\nTime: 1453 h\nDepth: 14.9 m\nDistance traveled: 333 m\nNo./ha\nNo.\ncaptured\nSpecies\nPrickly sculpin\n5\n46\nUnidentified Cottidae\n9\n82\n14\n128\nTOTAL\nH' = 0.94\nJ' = 0.94\nSTATION: CW21\nGear: 4.9-m Trawl\nDate: 7 Dec 1988\nTime: 1227 h\nDepth: 15.5 m\nDistance traveled: 333 m\nNo.\nNo./ha\nSpecies\ncaptured\nPeamouth\n2\n18\nUnidentified Cottidae\n1\n9\n27\nTOTAL\n3\nH' = 0.92\nJ' = 0.92","Appendix Table 4. --Continued.\nSTATION: CW22\nGear: 4.9-m Trawl\nDate: 7 Dec 1988\nTime: 1159 h\nDepth: 16.2 m\nDistance traveled: 296 m\nNo.\nNo./ha\nSpecies\ncaptured\nPrickly sculpin\n1\n10\nTOTAL\n1\n10\nH' = 0.00\nJ' = 1.00\nSTATION: CW23\nGear: 4.9-m Trawl\nDate: 7 Dec 1988\nTime: 1130 h\nDepth: 14.0 m\nDistance traveled: 296 m\nNo.\nNo./ha\nSpecies\ncaptured\nPrickly sculpin\n4\n41\nPeamouth\n1\n10\nTOTAL\n5\n51\nH' = 0.72\nJ' = 0.72"]}